There is convincing evidence that there is an increased risk of cardiovascular disease in patients infected with HIV. There are multiple potential risks for CVD in HIV infected patients; atherogenic lipid profiles have long been associated with increased risk of cardiovascular disease; elevations in total and LDL cholesterol have been demonstrated to be associated with such increased risk in the general population. More recent data suggest that elevations in levels of triglycerides and decreased levels of HDL cholesterol may be equally important markers of CVD risk. There is also emerging data that CVD is an inflammatory disease, and that HDL-C levels and subprofiles are mediated by inflammation; in HIV-infected individuals these changes may be exacerbated by the HIV infection. While treatment of atherogenic lipid profiles is desirable, attempts to treat these abnormalities in HIV infection are complex in HIV infected individuals. In studies done in populations with and without HIV, intake of high doses of omega three fatty acids is demonstrated to decrease triglycerides and may have a beneficial effect on HDL-cholesterol levels. Intake of omega three fatty acids alters lipid metabolism and may decrease inflammation by decreasing production of arachidonic acid. At present, there are no data that extend these observations to determine whether intake of omega three fats over a more prolonged time period will also have a beneficial impact on vascular function and surrogate markers of CVD in HIV infected patients. We propose a randomized, double blind trial of purified omega three fatty acids in HIV infected individuals with elevated levels of triglycerides. While the impact of omega three fatty acids on lipid profiles should be evident within 12 weeks, we propose to conduct this trial for a full 24 months to test our overall hypothesis that this intervention will not only improve triglyceride and HDL-C levels, improve HDL- subprofiles and membrane phospholipids and decrease inflammation, but will also improve brachial artery reactivity as a measure of vascular function at 24 weeks and lead to a reduced rate of progression of cIMT as a surrogate marker of CVD at 24 months when compared to controls. The specific aims of this proposal include: 1. to conduct a randomized, placebo controlled trial of omega three fatty acids over 24 months in HIV- infected individuals with elevated levels of triglycerides (> 150 mg/dl). 2. To demonstrate the impact of omega three fatty acid intake on TG levels and on HDL-C levels, HDL subprofiles, composition of membrane phospholipids, chronic inflammation as measured by CRP, sPLA2 and by levels of arachidonic acid. 3. To demonstrate the impact of omega three fatty acid intake on brachial artery reactivity at 24 weeks and on cIMT at 24 months. PUBLIC HEALTH RELEVANCE: There is convincing evidence that there is an increased risk of cardiovascular disease in patients infected with HIV. Treatment of lipid abnormalities in HIV infection is difficult in HIV and studies suggest that intake of high doses of omega three fatty acids may safely improve lipids and decrease inflammation. We propose a randomized, double blind trial of purified omega three fatty acids in HIV infected individuals with elevated levels of triglycerides to test our overall hypothesis that this intervention will not only improve lipids and decrease inflammation, but will also improve vascular function at 24 weeks and lead to a reduced progression of surrogate markers of CVD at 24 months.